Quantification of pro-inflammatory cytokines and osteoclastogenesis markers in successful and failed orthodontic mini-implants

Abstract Objectives: Miniscrew has been frequently used, considering that anchorage control is a critical point in orthodontic treatment, and its failure, the main adverse problem. Using two groups of stable (successful) and unstable (failed) mini-implants, this in vivo study aimed to quantify proinflammatory cytokines IL-1 α, IL-6, IL-17, and TNF-α and osteoclastogenesis marker RANK, RANKL, and OPG in gingival tissue, using the real-time polymerase chain reaction technique. Methodology: Thirteen patients of both sexes (11-49 years old) under orthodontic treatment were selected, obtaining 11 successful and 7 failed mini-implants. The mini-implants were placed and removed by the same surgeon, in both jaws. The mean time of permanence in the mouth was 29.4 months for successful and 7.6 months for failed mini-implants. At removal time, peri-mini-implant gingival tissue samples were collected and processed for quantification of the proinflammatory cytokines and osteoclastogenesis markers. Nonparametric Wilcoxon rank-sum test considering the clusters and Kruskal-Wallis test were used for statistical analysis (α=0.05). Results: No significant difference (p>0.05) was observed between the groups for either quantification of cytokines or osteoclastogenesis markers, except for IL-6 (p摘要 研究目的：微型种植体（miniscrew）已被广泛应用于正畸临床，支抗控制是正畸治疗的核心环节，而种植体脱落是其主要不良并发症。本体内研究设置稳定（成功）与不稳定（失败）微型种植体两组，旨在通过实时聚合酶链反应（real-time polymerase chain reaction）技术，定量检测牙龈组织中促炎细胞因子（proinflammatory cytokines）IL-1α、IL-6、IL-17、TNF-α以及破骨分化标志物（osteoclastogenesis marker）RANK、RANKL、OPG的表达水平。 研究方法：本研究纳入13例接受正畸治疗的男女患者（年龄11~49岁），共获取11枚成功种植体与7枚失败种植体。所有微型种植体均由同一名外科医生植入并取出，种植体分布于上下颌。成功组种植体的平均口内留存时间为29.4个月，失败组则为7.6个月。在取出种植体时，采集种植体周围牙龈组织样本，用于上述促炎细胞因子与破骨分化标志物的定量检测。统计分析采用考虑聚类效应的非参数Wilcoxon秩和检验与Kruskal-Wallis检验，检验水准α=0.05。 研究结果：两组间促炎细胞因子及破骨分化标志物的定量检测结果均无统计学差异（p>0.05），仅IL-6除外（原文未完整给出该指标的统计检验相关信息）。